/*
 * (C) Copyright 2014-2016, by Dimitrios Michail
 *
 * JHeaps Library
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.jheaps.monotone

import java.math.BigInteger

/**
 * Utilities for unsigned computation
 *
 * @author Dimitrios Michail
 */
internal object UnsignedUtils {
    private val UNSIGNED_MASK: Long = 0x7fffffffffffffffL

    @JvmStatic
    fun unsignedLongToDouble(x: Long): Double {
        var d: Double = (x and UNSIGNED_MASK).toDouble()
        if (x < 0) {
            d += 9.223372036854776E18
        }
        return d
    }

    @JvmStatic
    fun unsignedLongToBigInt(x: Long): BigInteger {
        var asBigInt: BigInteger = BigInteger.valueOf(x and UNSIGNED_MASK)
        if (x < 0) {
            asBigInt = asBigInt.setBit(java.lang.Long.SIZE - 1)
        }
        return asBigInt
    }
}
